1. Shear Repair of P/C Box Beams using CFRP Fabric KYDOT July 27, 2011 Salt Lake City, Utah Kentucky Transportation Cabinet Kentucky Transportation Center University of Kentucky RAC/TRB Summer Meeting

2. Objective Retrofit P/C Spread Box Beams using carbon fiber reinforced polymer (CFRP) fabric to increase Shear Capacity Retrofit P/C Spread Box Beams using carbon fiber reinforced polymer (CFRP) fabric to increase Shear Capacity

3. CFRP C LOTH/ F ABRIC

4. CFRP Fabric + Resin Steel Plate (A36 Steel) Ultimate Load = 3.25 kip 1” h CFRP = 0.0066” w CFRP = 0.0051 lb/ft w Steel = 0.19 lb/ft ≈ 37 w CFRP h Steel = 0.056” ≈ 8.5 h CFRP CFRP Fabric vs. Steel

5. Task #1 Material Testing

6. CFRP Fabric Test Specimens

7. Task #2 Beam Testing

8. 45 o Beam Strengthening

9. Beam Testing

11. Task #3 Field Application

12. Bridge on KY 3297 over Little Sandy River Carter County, Kentucky Shear Cracks in P/C Box Beams

13. Cracks Growing at an Alarming Rate SevereShearCracks

14. Original Solution Replace the Superstructure - Cost: ~ $600,000 - Close Bridge to Traffic

15. Alternate Solution Use CFRP Fabric Use CFRP Fabric - Cost: $105,000 (Design, Repair, and 3-years Monitoring) - Cost: $105,000 (Design, Repair, and 3-years Monitoring) - Bridge Remains Open to Traffic - Bridge Remains Open to Traffic

16. Placement of CFRP Fabric Step 1: Surface Preparation

17. Placement of CFRP Fabric Step 2: Crack Injection and Filling of Voids Crack Injection and Filling of Voids

18. Step 3: Apply Primer Placement of CFRP Fabric

19. Step 4: Apply Carbon Fabric Placement of CFRP Fabric

20. Step 5: CFRP Fabric on Outside Face Painted to Match Concrete Color Placement of CFRP Fabric

21. Task #4 Monitoring

22. Scaffolding Used for Monthly Bridge Monitoring Bridge Monitoring (10/01 to 12/06)

23. CFRP Fabric on Inside Faces of the Beams Was Not Painted to Match Concrete Color Crack Monitor

24. No Crack Movement Since Repair Was Completed in October 2001 Crack Monitor on Inside Beam Face

25. - Cost Effective: $105,000 for Repair vs. $600,000 for Replacement - Repair is Effective: No Crack Movement Since Repair was Completed in October 2001 - No Detour - No Traffic Control - No Traffic Disruption Conclusion !!!!! HURRAY !!!!!!

26. Associated Press November, 2001

27. The State Journal, December, 2001

28. The Daily Independent November 2001

29. Other CFRP Projects in KY n 9 Bridges Strengthened with CFRP n 3 Bridges Strengthened With Steel FRP

30. Thank You and Have a Nice Day

31. KY